Process for preparing silver halide emulsion utilizing a photographically useful additive capable of being deactivated and a deactivating agent therefor and silver halide photographic material prepared by the process

ABSTRACT

A process for preparing a silver halide photographic emulsion to be used for a photographic material is provided. Therein, additives such as dyes, sensitizers, auxiliary agents to be used upon gold sensitization, and so on are utilized within a period from at the silver halide grain forming time to just before the emulsion coating, and oxidizing agents are added at the time when the functions of the additives become substantially needless to result in conversion of the additives to those having no bad influences on photographic characteristics of the emulsion prepared, or to those having such chemical structures as to facilitate their removal with a washing treatment or the like. 
     Silver halide emulsions prepared by the described process are also disclosed.

TECHNICAL FIELD

The present invention relates to a process for preparing a silver halideemulsion and a silver halide photographic light-sensitive materialprepared by employing the process. More specifically, the inventionrelates to a process for preparing a silver halide emulsion using aphotographically useful additive capable of being deactivated and adeactivating agent therefor.

Deactivatable, photographically useful additives (which are referred toas an agent to be deactivated, hereinafter) which can be employed inthis invention include sensitizers (particularly sulfur-containingsensitizers), auxiliary agents to be used upon gold sensitization, andso on.

BACKGROUND ART

In the preparation of silver halide photographic emulsions, variousadditives are often used to change or improve photographic properties.

For instance, when methine dyes are employed at the time of preparingsilver halide grains, they can cause change of size or size distributionin silver halide grains prepared. Further, by preparing silver halidegrains in the presence of these compounds, it becomes possible toprepare grains difficult to produce under normal conditions such as AgClgrains having a (111) face, AgClBr grains having a (111) face, AgClgrains having a (110) face, AgClBr grains having a (110) face, AgBrgrains having a (110) face and AgBrI grains having a (110) face, or toform grains having a (111) face under pAg conditions which theoreticallyonly permits production of grains having a (100) face and to create thereverse of the above-described situation. Various crystal forms alsobecome possible by this technique such as sticks, spheres and tabularforms. Specific examples are described in, for example, Japanese PatentPublication No. 42737/80, West German Patent Application (OLS) No.2,932,185, Journal of Photographic Science, Vol. 21, p. 39 (1973), U.S.patent application Nos. 4,225,666, 4,183,756 and 2,735,766 andUnexamined Published Japanese Patent Application No. 23932/82. Further,the preparation of silver halide grains in the presence of methine dyesresults in a remarkable increase of adsorption strength of the dyes onthe grains. But at the same time, even if the so-obtained emulsions showexcellent properties in terms of fog, sensitivity and tone gradation,because of the difficulty of desorption of the thus-employed dyes, theemulsions cannot be spectrally sensitized with dyes of otherwavelengths. (That is, emulsions prepared using ortho dyes cannot beused as emulsions for regular wavelengths or panchromatic wavelengths.)

Further, even if silver halide emulsions of good monodispersibility orunusual crystal habits can be prepared by using desensitizing dyes,spectral sensitization cannot be performed unless the desensitizing dyesmay be removed.

The silver halide emulsion grains which are obtained by using dyes varyover a wide range, and as a result, the desired silver halide emulsiongrains cannot always be obtained with dyes of the desired spectrallysensitized wavelengths.

Moreover, when silver halide grains are prepared in the presence ofdyes, even if the obtained grains have good monodispersibility orregular forms, there are cases where fog easily occurs due to theemployed dyes, or subsequent chemical sensitization is stronglyinhibited or marked development inhibition may occur during development.

On the other hand, photographically useful additives such as sensitizersand auxiliary agents to be used at the time of gold sensitization fullyexert their effects at the time of or after the addition thereof in thecourse of preparing silver halide photographic emulsions to dischargetheir functions of changes or improvements in photographiccharacteristics. Thereafter, however, such additives become useless inmost cases, and when remain in the silver halide emulsions, some of themdo more harm than good to the photographic characteristics, to makematters worse.

As described above, the above-described various problems can beeliminated by speedily removing photographically useful additives afterthey are used for the preparation of silver halide emulsions, thusrendering them inactive.

Further, it is extremely difficult to completely remove and renderinactive compounds having adsorption to silver halides by means of theabove-described washing.

In particular, additives which have strong adsorption and which havestrong effects on the formation of silver halide grains could not beremoved by any known means.

In the light of the above-described circumstances, it has been stronglydemanded to develop a system by which photographically useful additivescan be smoothly removed and rendered inactive after they are used forthe preparation of silver halide emulsions.

DISCLOSURE OF INVENTION

An object of the present invention is to provide a novel process forpreparing a silver halide emulsion by which the above-described problemsconfronting the use of compounds which can be adsorbed by silver halidegrains or react therewith can be solved, and another object is toprovide a photographic light-sensitive material containing a silverhalide emulsion prepared using this novel process

As a result of searching examination, it has now been found that in theprocess of preparing a silver halide emulsion using a photographicallyuseful additive, which can be adsorbed by silver halide grains or reacttherewith, within a period from the silver halide grain-forming time tojust before the emulsion coating, the above-described objects areattained by using an oxidizing agent, which can lower or extinguish thefunction of the additive, that is, its adsorptive function or itsreactive function, by exerting a chemical action on the additive, at thetime when the function becomes unnecessary from the practical point ofview.

Also, it has been found that the above-described objects are attained byproviding at least one layer containing a silver halide emulsionprepared using combination of a photographically useful additivetherewith and an oxidizing agent of the kind which can lower orextinguish the function of the additive by exerting its action on theadditive at the time when the adsorptive or reactive function of theadditive becomes substantially needless.

That is, the present invention comprises using a photographically usefuladditive (referred to as an agent to be deactivated, hereinafter) in theprecipitating step, or at the time of physical or chemical ripening toachieve, e.g., control of the crystal face, the grain size and so onupon silver halide grain formation, or to have influences onphotographic characteristics (e.g., sensitivity, gradation, etc.) and,further, using an oxidizing agent at the time when thesephotographically useful functions become unnecessary or thephotographically useful additive comes to have rather undesirableeffects, far from being harmless, if remains in the silver halideemulsion, to achieve the lowering or extinguishing of the functions ofthe agent to be deactivated.

Although the idea of removing the additive to be used upon formation ofsilver halide grains and thereafter, to become needless, by carrying outa washing step has been proposed, the idea of extinguishing the functionof the additive by newly adding an oxidizing agent at a particular timeis quite new and cannot be found in conventional arts of makingemulsions.

In accordance with the present invention, it beccmes feasible to loweror extinguish the photographically useful functions of agents to bedeactivated by using oxidizing agents at specific times, respectively,whereby a wide variety of remarkable effects come to be achieved.

For example, it is now possible to easily deactivate additives (agentsto be deactivated) which could not be easily removed even by washingwith water and to render them incapable of showing any photographicallyadverse effects. Also, by deactivation, the additives can be convertedinto a form which can be easily removed by washing with water.

For example, use of oxidizing agents makes it possible to reduce oreliminate incorporation of agents to be deactivated into chemicalripening, to thereby reduce or eliminate their effects during thechemical ripening step. Because the additives are not incorporated intothe stage of development, adverse effects during development (e.g.,development restraining effects) can be eliminated. It is also possibleto prevent the agents to be deactivated from interfering with adsorptionof various additives such as sensitizing dyes, antifoggants, stabilizersand sensitizers which are employed up to immediately before the coatingof the emulsions.

Other advantages which can be obtained by using the present inventioninclude (i) emulsions having hard contrast can be obtained without anyloss of relative sensitivity, (ii) dissolution time can be shortened,(iii) sensitivity can be increased, and the like.

Exemplary dyes to be used in the present invention include methine dyessuch as cyanine dyes, merocyanine dyes, complex cyanine dyes, complexmerocyanine dyes, oxonol dyes, styryl dyes, hemicyanine dyes, hemioxonoldyes, merostyryl dyes, polymethine dyes containing streptocyanine andazapolymethine dyes wherein the methine group in the methine chain issubstituted by a nitrogen atom.

Exemplary cyanine dyes include 2 basic heterocyclic nuclei bonded bymethine condensation which are derived from quaternary salts such asquinolinium, pyridinium, isoquinolinium, 3H-indolium, benzo[e]indolium,oxazolium, oxazolinium, thiazolinium, thiazolium, selenazolium,selenazolinium, benzoxazolium, benzothiazolium, selenazolium,imidazolium, imidazolinium, benzimidazolium, naphthoxazolium,naphthothiazolium, naphthoselenazolium, naphthoimidazolium,dihydronaphthothiazolium, dihydronaphthoselenazolium, pyrylium,imidazopyrazinium, imidazo[4,5-b]quinoxalium, pyrrolidinium and indolenucleus and the like, and generally include cyanine dyes which are usedfor the purpose of effecting spectral sensitization or increasingstabilization (e.g., fog prevention) of silver halide emulsions.

Merocyanine dyes include those compounds formed by condensation bymethine bond of basic nuclei which are used for cyanine dyes and acidicnuclei which are derived from barbituric acid, 2-thiobarbituric acid,rhodanine, hydantoin, 2-thiohydantoin, 2-pyrazoline-5-one,2-ixooxazoline-5-one, indane-1,3-dione, cyclohexane-1, 3-dione,1,3-dioxane-4,6-dione, pyrazoline-3,5-dione,2-thiooxazolidine-2,4-dione, pentane-2,4-dione,alkylsulfonylacetonitrile, arylsulfonylacetonitrile, malonic aciddiester, malononitrile, iso-quinoline-4-one, chroman-2,4-dione,pyrazolo[5,1-b]quinazoline and the like.

The dyes to be used in accordance with the present invention aredescribed in the following literature: F. M. Hamer, The Chemistry ofHeterocyclic Compounds, Vol. 18, The Cyanine Dyes and Related Compounds,A. Weissberger ed., Interscience, New York, 1964; D. M. Sturmer, TheChemistry of Heterocyclic Compounds, Vol. 30, A. Weissberger and E. C.Taylor eds., John Wiley, New York, 1977, p. 441; Research Disclosure17643, 23-24 (1978), West German Pat. No. 929,080, U.S. Pat. Nos.2,231,658, 2,493,748, 2,503,776, 2,519,001, 2,912,329, 3,656,959,3,672,897, 3,694,217, 4,025,349 and 4,046,572, British Pat. No.1,242,588, Japanese Patent Publication Nos. 14030/69 and 24844/77,British Pat. Nos. 584,609 and 1,177,429, Unexamined Published Japanesepatent Application Nos. 85130/73, 99620/74, 114420/74 and 108115/77,U.S. Pat. Nos. 2,274,782, 2,533,472, 2,956,879, 3,148,187, 3,177,078,3,247,127, 3,540,887, 3,575,704, 3,653,905, 3,718,472, 4,071,312 and4,070,352 and the like.

The methine dyes to be used in the present invention, which are added inthe formation of grains and chemical sensitization and which aredeactivated by deactivating agents such as oxidizing agents insubsequent steps, are termed "methine dyes" herein since they belong tothe same group in terms of chemical structure. The methine dyes may beeither colored or colorless. In other words, absorption of visible lightis not an essential requirement; what is required of these dyes is toinfluence grain formation or chemical sensitization and to exertpreferable effects on the sensitivity and stability of photographicmaterials. Thus, in some cases dyes which do not absorb visible lightare more preferable in relation to the particular type of equipment usedfor the preparation of photographic materials.

In accordance with the present invention, when color carriers (agents tobe deactivated) are used in the formation of silver halide grains (e.g.,precipitation and physical ripening processes) or chemicalsensitization, use of the oxidizing agents of the present inventionmakes it possible to deactivate the adsorption of the dyes to silverhalides or to decompose the dyes. As a result, the above-describedvarious defects can be eliminated.

In the present invention, the term "dyes" includes sensitizing dyes(spectral sensitizing dyes), dyes in an ordinary sense, desensitizingdyes and the like.

Among the dyes to be used in the present invention, cyanine dyes,merocyanine dyes and rhodacyanine dyes are preferred.

Examples of particularly preferred dyes to be used in the presentinvention include those of formulae (D-I), (D-II), (D-III) and (D-IV):##STR1## wherein Q¹ and Q² may be the same or different, and eachrepresents a group of atoms which are required to form cyclic nucleiderived from basic heterocyclic compounds generally used for cyaninedyes such as oxazoline, oxazole, benzoxazole, naphthoxazole (e.g.,naphtho[2,1-d]oxazole, naphtho[1,2-d]oxazole, naphtho-[2,3-d]oxazole),thiazoline, thiazole, benzothiazole, naphthothiazole (e.g.,naphtho[1,2-d]thiazole, naphtho[2,1-d]thiazole andnaphtho[2,3-d]thiazole), dihydronaphthothiazole (e.g.,8,9-dihydronaphtho[1,2-d]thiazole), selenazoline, selenazole,benzoselenazole, naphthoselenazole (e.g., naphtho[1,2-d]selenazole, andnaphtho[2,1-d]selenazole), 3H-indole (e.g., 3,3-dimethyl-3H-indole),benzindole, imidazoline, imidazole, benzimidazole, naphthoimidazole(e.g., naphtho[1,2-d]-imidazole and naphzho[2,3-d]imidazole), pyridine,quinoline, imidazo[4,5-b]quinoxaline, pyrrolidine and the like. Theabove-illustrated nuclei may have one or two or more varioussubstituents on the rings. Exemplary substituents include a hydroxygroup, a halogen atom (e.g., fluorine, chlorine, bromine and iodine), analkyl group or a substituted alkyl group (e.g., methyl, ethyl, propyl,isopropyl, butyl, cyclohexyl, octyl, decyl, octadecyl, 2-hydroxyethyl,3-sulfopropyl, carboxymethyl, ethoxycarbonylmethyl,ethoxycarbonylmethyl, 2-cyanoethyl, trifluoromethyl, methoxymethyl,benzyl and phenethyl), an aryl group or a substituted aryl group (e.g.,phenyl, 1-naphthyl, 2-naphthyl, 4-sulfophenyl, 3-carboxyphenyl,4-biphenyl, tolyl, anisyl, 4-chlorophenyl, 2-thienyl, 2-furyl, 2-pyridyland 4-pyridyl), an alkoxy group or a substituted alkoxy group (e.g.,methyl, ethyl, isopropoxy, decyloxy and 2-methoxyethoxy), an aryloxygroup (e.g., phenoxy, 1-naphthoxy, 4-methoxyphenoxy, 4-methylphenoxy and3-chlorophenoxy), an alkylthio group (e.g., methylthio, ethylthio,butylthio and decylthio), an arylthio group (e.g., phenylthio,p-tolylthio, p-anisylthio and 2-naphthylthio), a methylenedioxy group, acyano group, an alkenyl group or a substituted alkenyl group (e.g.,vinyl, 1-butenyl and styryl), an amino group or a substituted amincgroup (e.g., anilino, dimethylamino, diethylamino, morpholino,moncmethylamino, bis(hydroxyethyl)amino, acetamido, benzoylamido andmethylsulfonylamino), a nitro group, a carboxy group, an alkoxycarbonylgroup (e.g., methoxycarbonyl and erhoxycarbonyl), an acyl group (e.g.,acetyl, benzoyl, propionyl, methylsulfinyl and methylsulfonyl), a sulfogroup and the like.

G¹ and G² may be the same or different, and each represents an alkylgroup, an aryl group and an alkenyl group, which may be eithersubstituted or unsubstituted. Exemplary groups include methyl, ethyl,propyl, isopropyl, butyl, octyl, decyl, octadecyl, methoxyethyl,2-ethoxyethyl, 2-hydroxyethyl, carboxymethyl, 2-carboxyethyl,3-carboxypropyl, 2-sulfoethyl, 3-sulfopropyl, 3-sulfobutyl,4-sulfobutyl, 4-sulfophenyl, 2-sulfatoethyl, 3-thiosulfatopropyl,2-phosphonoethyl, chlorophenyl, allyl, 1-butenyl, 2,2,2-trifluoroethyl,2,2,3,3-tetrafluoropropyl, phenethyl, 4-sulfophenethyl, 2-chloropropyl,2-hydroxy-3-sulfopropyl, ethoxycarbonylmethyl and the like.

G³ is a hydrogen atom or a fluorine atom, provided that when n² is not0, G³ represents an alkyl group or a substituted alkyl group (e.g.,methyl, ethyl methoxyethyl) and that G³ may form a 5- or 6-membered ringby cross-linking with G¹ via alkylene.

G⁴ and G⁵ are each a hydrogen atom, a substituted or unsubstituted loweralkyl group (e.g., methyl, ethyl, propyl, methoxyethyl, benzyl andphenethyl) and an aryl group (e.g., phenyl, anisyl and tolyl).

n¹ and n³ are each 0 or 1, and n² is 0, 1, 2 or 3.

Y¹ is a cationic group; W¹ is an anionic group; k¹ and k² are each 0 or1, which depends on the presence or absence of ionic substituents. G³and G⁵, G⁴ and G⁴ (when n² is 2 or 3), G⁵ and G⁵ (when n² is 2 or 3) andG² and G⁵ may, when taken together, respectively represent atoms whichare required to complete alkylene cross-linking. ##STR2## wherein Q³ isthe same as either Q¹ or Q² of formula (D-I); G¹⁰ is the same as eitherG¹ or G² of formula (D-I); G¹¹ and G¹² are each a hydrogen atom, asubstituted or unsubstituted lower alkyl group (e.g., methyl, ethyl,propyl, methoxyethyl, benzyl, phenethyl, 2-hydroxyethyl and2-carboxyethyl), an aryl group (e.g., phenyl, naphthyl, 2-carboxyphenyl,tolyl and 4-chlorophenyl) and a halogen atom (e.g., fluorine andchlorine). Any two which are arbitrarily chosen from G¹⁰, G¹¹ and G¹²may represent elements which are required to complete alkylenecross-linking.

G¹³ and G¹⁴ may be the same or different and each represents an electronattractive group. Examples of such groups include a cyano group, analkyl or arylsulfonyl group (e.g., methylsulfonyl, phenylsulfonyl,tolylsulfonyl and octylsulfonyl), a carboxy group, an alkyl orarylcarbonyl group (e.g., acetyl, propionyl, decanoyl, benzoyl,tricarbonyl and 2-thienylcarbonyl), a 5- or 6-memberednitrogen-containing heterocyclic group (e.g., 2-thiazolyl,2-benzothiazolyl, 2-benzimidazolyl, 2-pyridyl and 2-benzoselenazolyl).G¹³ and G¹⁴ may, when taken together, represent a group of atoms whichare required to complete a cyclic acidic nucleus generally used formerocyanine dyes, oxonol dyes and hemicyanine dyes such as2,4-oxazolidinedione (e.g., 3-ethyl-2,4-oxazolidinedione),2,4-thiazolidinedione (e.g., 3-butyl-2,4-thiazolidinedione),2-thio-2,4-oxazolidinedione (e.g.,3-phenyl-2-thio-2,4-oxazolidinedione), rhodanine (e.g.,3-ethylrhodanine, 3-carboxymethylrhodanine, 3-(2-sulfoethyl)rhodanine,3-phenylrhodanine, 3-furfurylrhodanine,3-(3-dimethylaminopropyl)rhodanine, 3-(2-ethoxyethyl)rhodanine and3-benzylrhodanine), hydantoin (e.g., 1,3-diethylhydantoin),2-thiohydantoin (e.g., 1,3-diethyl- 2-thiohydantoin,1-ethyl-3-phenyl-2-thiohydantoin,1-(2-hydroxyethyl)-3-phenyl-2-thiohydantoin,1-[2-(2-hydroxyethoxy)ethyl]-3-(2-pyridyl)-2-thiohydrantoin and1-N-(2-hydroxyethyl)aminocarbonylmethyl-3-phenyl-2-thiohydantoin),2-pyrazoline-5-one (e.g., 3-methyl-1-phenyl-2-pyrazoline-5-one,3-methyl-1-(4-carboxybutyl)-2-pyrazoline-5-one and3-methyl-1-(4-sulfophenyl)-2-pyrazoline-5-one), 2-isooxazoline-5-one(e.g , 3-phenyl-2-isooxazoline-5-one), 3,5-pyrazolidinedione (e.g.,1,2-diphenyl-3,5-pyrazolidinedione), 1,3-indanedione,1,3-dioxane-4,6-dione, 1,3-cyclohexanedione, pyrazolo[5,1-b]quinazoline,pyrazolo[5,1-b]quinazolone, barbituric acid (e.g., 1,3-diethylbarbituricacid) and 2-thiobarbituric acid (e.g., 1,3-diethylbarbituric acid and1,3-bis(2-methoxyethyl)-2-thiobarbituric acid). n⁴ is 0 or 1; and n⁵ is0, 1, 2 or 3. ##STR3## wherein Q⁴ and Q⁶ are each the same as either Q¹or Q² of formula (D-I); G²¹ and G²² are each the same as either G¹¹ orG¹² of formula (D-II); G²³ and G²⁴ are each the same as either G⁴ or G⁵of formula (D-I); and G²⁵ and G²⁶ are each the same as G¹ or G² offormula (D-I). G⁵ represents elements required to complete anitrogen-containing 5-membered ring. Examples of suchnitrogen-containing 5-membered rings include 4-oxooxazolidine,4-oxothiazolidine, 4-oxoimidazolidine and the like. G²⁵ and G²⁶ are eachthe same as either G¹ or G² of formula (D-I); G²⁷ is an alkyl group, anaryl group and an alkenyl group, which may be either substituted orunsubstituted. Examples of such groups include methyl, ethyl, propyl,isopropyl, butyl, octyl, decyl, octadecyl, methoxyethyl, 2-ethoxyethyl,2-hydroxyethyl, carboxyethyl, 2-carboxyethyl, 3-carboxypropyl,2-sulfoethyl, 3-sulfopropyl, 4-sulfobutyl, 2-cyanoethyl,2-carbamoylethyl, 2,2,2-trifluoroethyl, allyl, phenethyl, 4-sulfophenyl,2-ethoxycarbonylmethyl, 2-pyridyl, 2-furyl, furfuryl, phenyl,4-carboxyphenyl, tolyl, anisyl and the like. n⁶ and n⁹ are each 0 or 1;n⁷ is 0, 1 or 2; n⁸ is 0, 1 or 2; Y² is a cationic group; W² is ananionic group; k³ and k⁴ are each 0 or 1, which depends on the presenceor absence of ionic substituents. ##STR4## wherein Q⁷ representselements required to complete indole, pyrrolopyridine, pyrrolopyrimidineor pyrazolopyridine, provided that these compounds may have substituentson the heterocyclic nucleus. Examples of such substituents includenitro, cyano, trifluoromethyl, halogen, lower alkyl, lower alkoxy andthe like. Q⁸ is the same as either Q¹ or Q² of formula (D-I); G³³ ishydrogen, aryl (e.g., phenyl, p-nitrophenyl, p-cyanophenyl and tolyl),ethoxycarbonyl, methoxycarbonyl, halogen, lower alkyl, and lower alkoxy;Y³ is a cationic group; W³ is an anionic group; k⁵ and k⁶ are each 0 or1; depending on the presence or absence of ionic substituents; and n¹⁰is 0 or 1.

Typical examples of the dyes to be used in the present invention arelisted below: ##STR5##

Exemplary sensitizers to be used in the present invention includesulfur-containing sensitizers such as thiosulfates (e.g., sodiumthiosulfate, etc.), thioureas (e.g., allylthiourea, diphenylthiourea,triethylthiourea, etc.), rhodanines (e.g.,5-benzylidene-3-propylrhodanine, etc.) and the like. Specific examplesare described in U.S. Pat. Nos. 1,574,944, 2,410,689, 2,278,947,2,728,668 and 3,656,955, Research Disclosure (RD 17643), page 23, Item 3(December, 1978), and the like.

Gold sensitization aids to be used in the present invention arecompounds which may act as ligands of gold ions such assulfur-containing sensitizers.

These gold sensitization aids, after being used in large quantitiesduring the preparation of silver halide emulsions (e.g., chemicalripening and grain formation processes), can be deactivated by allowingoxidizing agents to act on them at any stage up to immediately beforecoating. By this deactivation, it is possible to stabilize photographicproperties during dissolution or to increase stability of silver halideemulsions coated on supports during storage of photographiclight-sensitive materials over a period of time.

Oxidizing agents, which are the vital point of the present invention,have the ability to act upon agents to be deactivated so as to lower orextinguish their photographically useful functions.

More specifically, compounds which are chemically inert towards theoxidation reduction potentials of the agents to be deactivated areemployed effectively as oxidizing agents.

Useful oxidizing agents to be used in the present invention includeinorganic oxidizing agents, organic oxidizing agents and the like.

Specific examples of oxidizing agents are shown below.

Inorganic oxidizing agents include oxyacid salts such as hydrogenperoxide (water), adducts of hydrogen peroxide (e.g., NaBO₂.H₂ O₂. 3H₂O, 2NaCO₃.3H₂ O₂, Na₄ P₂ O₇.2H₂ O₂ and 2Na₂ SO₄.H₂ O₂.2H₂ O, etc.),peroxy acid salts (e.g., K₂ S₂ O₈, K₂ C₂ O₆ and K₄ P₂ O₈, etc.), peroxycomplex compounds (e.g., K₂ [Ti(O₂)C₂ O₄ ].3H₂ O, 4K₂SO₄.Ti(O₂)OH.SO₄.2H₂ O and Na₃ [VO(O₂)(C₂ C₄)₂.6H₂ O, etc.),permanganates (e.g., KMnO₄, etc.) and chromates (e.g., K₂ Cr₂ O₇, etc.).

The organic oxidizing agents include organic peroxides (e.g., peraceticacid and perbenzoic acid, etc.).

Further, oxidizing compounds such as oxidizing gases (e.g., ozone andoxygen gas, etc.), halogen releasing oxidizing compounds (e.g., sodiumhypochlorite, N-bromosuccinimide and chloramine B (sodiumbenzenesulfonchloramide), chloramine T (sodiumparatoluenesulfonchloramide), etc.) may also be employed.

Among the above-illustrated oxidizing agents, inorganic oxidizing agentsand oxidizing gases are preferred, with inorganic oxidizing agents beingparticularly preferred. Among the inorganic oxidizing agents, hydrogenperoxide or adducts or precursors thereof are particularly preferred.

Most of these oxidizing agents are commercially available, and they canalso be easily synthesized.

Preferred oxidizing agents to be used in the present invention arecompounds which deactivate photographically useful functions of agentsto be deactivated and which at the same time do not decompose gelatin ordo not have strong desensitizing effects.

For example, when the agents to be deactivated are dyes, oxidizingagents applicable to the objects of the present invention can be mosteasily selected by checking whether they remove color when they areadded to the dye solutions. Another requirement for the oxidizing agentsto be used in the present invention is that they decompose dyes, whileproducts of such decomposition or the oxidizing agents themselves do notexert any strongly adverse effects on the photographic properties.

Some dyes lose color and become desorbed even by simple acids (e.g.,inorganic acids such as nitric acid, sulfuric acid and hydrochloricacid, and organic acids such as acetic acid), but these dyes need to bedecomposed so that they will not regain color and be absorbed againafter environmental changes (e.g., pH changes).

In accordance with the present invention, the oxidizing agents may beallowed to act in the presence of catalysts such as: metal salts such astungsten salts (e.g., sodium tungstate and tungsten trioxide, etc.),vanadium salts (e.g., pervanadic acid and vanadium pentoxide, etc.),osmium salts (e.g., osmium tetroxide, etc.), molybdenum salts, manganesesalts, iron salts and copper salts, etc.; selenium dioxide; and enzymes(e.g., catalase), etc. Among these catalysts, salts (containing oxides)of heavy metal and noble metal are preferable. These catalysts may beadded prior to the addition of oxidizing agents or they may be employedat the time of the addition of oxidizing agents or thereafter. Since theaction of oxidizing agents can be accelerated by these catalysts,deactivation (i.e., lowering or extinguishing of the functions) can beeffected in the shorter time. The catalysts are usually used in amountsof about 10 mg to 1 g per mol of Ag.

In accordance with the present invention, oxidizing agents can beallowed to act in the presence of salts other than silver salts andhalides. Exemplary salts include inorganic salts (e.g., nitrates such aspotassium nitrate and ammonium nitrate, etc., sulfates such as potassiumsulfate and sodium sulfate, etc., and phosphates, etc.) and organicsalts (e.g., potassium acetate, sodium acetate and potassium citrate,etc.), and the like. These salts may be added to solutions of silversalts or halides beforehand. These salts are usually employed in amountsof about 1 to 20 g per mol of Ag.

Exemplary stabilizers to be used in the present invention includephosphoric acid, barbituric acid, uric acid, acetanilide, oxyquinoline,sodium pyrophosphate and sodium stannate, etc.

The amounts of addition of agents to be deactivated to be used in thepresent invention can be arbitrarily determined depending on the kindsof the agents to be deactivated, the time of addition, halogencomposition of the silver halide grains, grain size and other factors,but preferred amounts are selected from the range of 10⁻⁸ to 1 mol permol of silver halide, and the range of 10⁻⁷ to 10⁻¹ mol per mol ofsilver halide is more preferred.

For example, when dyes are added as agents to be deactivated, they areadded in amounts ranging from 10⁻⁸ to 10⁻² mol per mol of silver halide,and more preferably from 10⁻⁷ to 10⁻³ mol per mol of silver halide.

The amounts of addition of the oxidizing agents to be used in thepresent invention can vary according to the kinds and amounts of theagents to be deactivated, the time of addition and other factors. In thecase where it is necessary to completely eliminate the functions ofagents to be deactivated, the oxidizing agents must be added inequimolar amounts or more with respect to the agents to be deactivated.On the other hand, in the case where the agents to be deactivated needto be deactivated to a specific extent, the amounts of addition aredetermined according to the particular purposes. Generally, oxidizingagents can be employed in amounts ranging from 1/100 to 3,000 molartimes, based on the agents to be deactivated.

For example, when dyes are used as agents to be deactivated, oxidizingagents can be added in amounts ranging from 1/10 to 3,000 molar times,and preferably 1/5 to 1,000 molar times.

In accordance with the present invention, agents to be deactivated aretypically employed during the period from the formation of silver halidegrains to the completion of chemical ripening, and preferably employedduring the period from the formation of silver halide grains to thecommencement of chemical ripening.

In the case where the agents to be deactivated are dyes, they arepreferably used from the formation of silver halide grains to thecommencement of the washing process (particularly during theprecipitation and physical ripening processes).

Further, in the case where agents to be deactivated are sensitizers andauxiliary agents to be used upon gold sensitization, they are preferablyadded in the chemical ripening process.

The agents to be deactivated as well as the oxidizing agents are addedto silver halide emulsions in the form of solutions in water or organicsolvents (e.g., alcohols, ethers, glycols, ketones, esters and amides,etc.). They can also be added in the form of powder dispersions inhydrophilic colloids such as gelatin.

Oxidizing agents can be added to the system either before or afteraddition of agents to be deactivated or both before and after, but arepreferably added after addition of agents to be deactivated.

Addition of oxidizing agents can be performed at any stage from theformation of silver halide grains up to immediately before coating, butis basically effected after the photographically useful functions ofagents to be deactivated have become no longer required. In the casewhere chemical ripening is carried out using chemical sensitizers,oxidizing agents are preferably added before the start of chemicalripening.

Preferred embodiments of using the oxidizing agents and agents to bedeactivated will now be described below.

In the case where dyes are used as agents to be deactivated, thefollowing procedures (1) to (3) may be employed:

(1) A silver halide emulsion having a specific crystal habit is formedby incorporating a dye during the formation of silver halide emulsiongrains, and an oxidizing agent is allowed to act at some point duringthe period up to immediately before coating (preferably before the startof chemical ripening).

(2) A silver halide emulsion having high monodispersibility or aspecific crystal habit is formed by growing silver halide emulsiongrains in the presence of a dye during the formation of such grains, andan oxidizing agent is allowed to act at some point during the period upto immediately before coating (preferably before the start of chemicalripening).

(3) After allowing an oxidizing agent to act as in Procedure (1) or (2),a dye having different characteristics is added at some point during theperiod up to immediately before coating.

In the case where the agents to be deactivated are dyes, they arepresumably decomposed by oxidation by the deactivating agents of thepresent invention, and as a result, their functions such as adsorptionto silver halide grains are eliminated.

The agents to be deactivated of the present invention may be employed ina combination of two or more, as required. The oxidizing agents can alsobe employed in a combination of two or more as desired.

Further, when the oxidizing agents to be used in the present inventionare added in large quantities, reducing substances which are substanceshaving a reduction action to an oxidizing agent to be used in thepresent invention (e.g., sulfites, sulfinates and reducing sugars, etc.)are added at some appropriate stage to deactivate the residual excessoxidizing agents to avoid any adverse effects on subsequent chemicalripening, etc.

The amounts of the reducing substances to be added vary depending on thekinds of the oxidizing agents to be used and the desired degree ofdeactivation, but they are typically employed in equimolar amounts ormore based on the oxidizing agents, and preferably in the range of 1 to50 mols per mol of the oxidizing agents.

It has been conventionally known to use oxidizing agents in thepreparation of silver halide emulsions. For example, in regard to heatdevelopable light-sensitive materials, it is known to use halogenreleasing oxidizing agents in the halogenation process to prepare silverhalides from silver carboxylate. It is also known to add oxidizingagents in normal silver halide emulsions or the above-described heatdevelopable light-sensitive materials for fog prevention. Examples ofsuch methods are described in Japanese Patent Publication Nos. 40484/78and 35488/79, Unexamined Published Japanese Patent Application Nos.4821/77, 10724/74 and 45718/74. However, the purposes and advantages ofusing these oxidizing agents are completely different from those of thepresent invention.

The photographic emulsions of the present invention may incorporate anyof silver bromide, silver iodobromide, silver iodochlorobromide, silverchlorobromide, silver iodide and silver chloride as a silver halide.

The grain size distribution may be either broad or narrow.

Silver halide grains in the photographic emulsions may have a regularcrystal form such as a cube, an octahedron, a tetradecahedron, a rhombicdodecahedron, etc., an irregular crystal form such as a sphere, a plate,etc., or a composite form thereof. Silver halide grains may be a mixtureof grains having various crystal forms.

Also, tabular grains having a diameter/thickness ratio of 3 or more,preferably from 5 to 20, may be employed. In this case, the tabulargrains can be present in the emulsion in such a content as to form 50%or more of the whole grains, based on the projected area. Details ofsuch grains are described in U.S. Pat. Nos. 4,434,226 and 4,439,520,European Pat. No. 84,637 A2, Gutoff, Photographic Science andEngineering, Vol. 14, pp. 248-257 (1970), and so on.

The silver halide grains may differ in phase between the inside thereofand the surface portion thereof or may be homogeneous.

Further, the silver halide grains may also include junction type silverhalide crystals composed of an oxide crystal, e.g., PbO, and a silverhalide crystal, e.g., silver chloride, epitaxially grown silver halidecrystals (e.g., a silver bromide crystal on which silver chloride,silver iodobromide, silver iodide, etc., is epitaxially grown) andcrystals of hexagonal or silver iodide on which hexahedral silverchloride is orientatedly overgrown.

The silver halide grains in the photographic emulsion can have anoptional grain size distribution and may be a monodispersed. The term"monodispersed" herein means a dispersion system wherein more than 95%of the total silver halide grains are included in the size range within±60%, preferably 40%, of the number mean grain size. The term "numbermean grain size" herein used means the number mean diameter of theprojected areas of the total silver halide grains.

The photographic emulsions according to the present invention can beprepared by the methods as described in P. Glafkides, Chimie et PhysiquePhotographique (Paul Montel, 1967), G. F. Duffin, Photographic EmulsionChemistry (The Focal Press, 1966), V. L. Zelikman et al., Making andCoating Photographic Emulsion, (The Focal Press, 1964), etc. That is,photographic emulsions can be prepared according to any of the acidprocess, the neutral process, the ammonia process, and the like. Methodsfor reacting a water-soluble silver salt with a water-soluble halideinclude a single jet method, a double jet method and a combinationthereof.

In addition, a method in which silver halide grains are produced in thepresence of excess silver ions (the reverse mixing method) can also beemployed. Further, the controlled double jet method, in which the pAg ofthe liquid phase wherein silver halide grains are to be precipitated ismaintained constant, may also be employed. According to this method,silver halide emulsions in which grains have a regular crystal form andan almost uniform size distribution can be obtained.

Two or more silver halide emulsions prepared separately may be used inthe form of a mixture.

It is preferred that the silver halide emulsions to be used in thepresent invention are substantially of a surface latent image type.

The term "substantially of a surface latent image type" is defined thatwhen the emulsion, after exposure to light for 1 to 1/100 sec, isdeveloped by the processes of surface development (A) and internaldevelopment (B) as shown below, the sensitivity obtained by surfacedevelopment (A) is larger than the sensitivity obtained by internaldevelopment (B). The term "sensitivity" as used herein is defined asfollows:

    S=100/Eh

wherein S is sensitivity, and Eh is the exposure dose required toprovide a density which is exactly halfway between the maximum density(Dmax) and the minimum density (Dmin): 1/2(Dmax+Dmin).

Surface Development (A)

A photographic emulsion is developed in a developer having the followingcomposition at 20° C. for 10 min:

    ______________________________________                                        N--Methyl-p-aminophenol (hemisulfate)                                                                   2.5   g                                             Ascorbic Acid             10    g                                             Sodium Metaborate.4H.sub.2 O                                                                            35    g                                             Potassium Bromide         1     g                                             Water to make             1     liter                                         ______________________________________                                    

Internal Development (B)

A photographic emulsion is treated in a bleaching solution containing 3g/l of red prussiate and 0.0125 g/l of phenosafranine at about 20° C.for 10 min, followed by washing with water for 10 min. The photographicemulsion is then developed in a developer having the followingcomposition at 20° C. for 10 min:

    ______________________________________                                        N--Methyl-p-aminophenol (hemisulfate)                                                                   2.5   g                                             Ascorbic Acid             10    g                                             Sodium Metaborate.4H.sub.2 O                                                                            35    g                                             Potassium Bromide         1     g                                             Sodium Thiosulfate        3     g                                             Water to make             1     liter                                         ______________________________________                                    

In the formation of silver halide grains or physical ripening of thegrains, cadmium salts, zinc salts, lead salts, thallium salts, iridiumsalts or complexes thereof, rhodium salts or complexes thereof, ironsalts or complexes thereof and the like may be present. The amount ofthese salts or complexes may be either small or large depending on thedesired light-sensitive material.

Removal of soluble salts from the silver halide emulsion after theformation of silver halide grains or physical ripening can be effectedby the noodle washing method comprising gelling the gelatin or asedimentation method (or a flocculation method) using an inorganic salt,an anionic surface active agent, an anionic polymer (e.g.,polystyrenesulfonic acid) or a gelatin derivative (e.g., acylatedgelatin, carbamoylated gelatin, etc.).

The silver halide emulsion may or may not be chemically sensitized.Chemical sensitization can be carried out using processes as describedin, for example, H. Frieser (ed.), Die Grundlagen der PhotographischenProzesse mit Silberhalogeniden (Akademische Verlagsgesellschaft, 1968),pp. 675-734.

More specifically, chemical sensitization can be carried out by sulfursensitization using compounds containing sulfur capable of reacting withactive gelatin or silver (e.g., thiosulfates, thioureas, mercaptocompounds, rhodanines, etc.), reduction sensitization using reducingsubstances (e.g., stannous salts, amines, hydrazine derivatives,formamidinesulfinic acid, silane compounds, etc.), noble metalsensitization using noble metal compounds (e.g., gold complexes andcomplexes of Periodic Table Group VIII metals such as Pt, Ir, Pd, etc.).

Specific examples of sulfur sensitization are described in U.S. Pat.Nos. 1,574,944, 2,410,689, 2,278,947, 2,728,668 and 3,656,955, etc.Specific examples of reduction sensitization are described in U.S. Pat.Nos. 2,983,609, 2,419,974 and 4,054,458, etc. Specific examples of noblemetal sensitization are given in U.S. Pat. Nos. 2,399,083 and 2,448,060,British Pat. No. 618,061, etc.

Photographic emulsions according to the present invention can containvarious compounds for the purpose of preventing fog in preparation,storage or photographic processing, or for stabilizing photographicproperties. Such compounds include azoles, such as benzothiazoliumsalts, nitroindazoles, triazoles, benzotriazoles, benzimidazoles(particularly nitro- or halogen-substituted ones); heterocyclic mercaptocompounds, such as mercaptothiazoles, mercaptobenzothiazoles,mercaptobenzimidazoles, mercaptothiadiazoles, mercaptotetrazoles(particularly 1-phenyl-5-mercaptotetrazole) and mercaptopyrimidines; theabove-described heterocyclic mercapto compounds having water-solublegroups such as a carboxyl group, a sulfonyl group or a like group;thioketo compounds, such as oxazolinethione; azaindenes, such astetraazaindenes (particularly 4-hydroxy-substituted(1,3,3a,7)tetraazaindenes); benzenethiosulfonic acids; benzenesulfinicacids; and many other compounds known as antifoggants or stabilizers.

For details of these compounds, disclosure given in, for example, E. J.Birr, Stabilization of Photographic Silver Halide Emulsions (FocalPress, 1974) can be referred to.

Photographic emulsions of the light-sensitive materials of the presentinvention may be spectrally sensitized to blue light, green light or redlight having relatively long wavelengths or infrared ray usingsensitizing dyes. Sensitizing dyes which can be used for spectralsensitization include cyanine dyes, merocyanine dyes, complex cyaninedyes, complex merocyanine dyes, holopolar cyanine dyes, styryl dyes,hemicyanine dyes, oxonol dyes, hemioxonol dyes and the like. Specificexamples of the spectral sensitizing dyes are described in, for example,P. Glafkides, Chimie Photographique (2nd Ed., 1957; Paul Montel, Paris),Chapters 35-41, F. M. Hamer, The Cyanine and Related Compounds(Interscience), U.S. Pat. Nos. 2,503,776, 3,459,553 and 3,177,210 andResearch Disclosure, Vol. 176, 17643 (December, 1978), Item 23, IV-J.

The sensitizing dyes may be used either singly or in combination. Inparticular, combinations of sensitizing dyes are often used for thepurpose of supersensitization. Typical examples of such combinations aredescribed in U.S. Pat. Nos. 2,688,545, 2,977,229, 3,397,060, 3,522,052,3,527,641, 3,617,293, 3,628,964, 3,666,480, 3,672,898, 3,679,428,3,703,377, 3,769,301, 3,814,609, 3,837,862 and 4,026,707, British Pat.Nos. 1,344,281 and 1,507,803, Japanese Patent Publication Nos. 4936/68and 12375/78 and Unexamined Published Japanese Patent Application Nos.110618/77 and 109925/77.

In addition to sensitizing dyes, the photographic emulsions mayincorporate dyes which do not have spectral sensitization effects inthemselves or substances which do not substantially absorb visible lightand which show supersensitization effects. Examples of such substancesinclude aminostilbene compounds which are substituted withnitrogen-containing heterocyclic groups, such as those described in U.S.Pat. Nos. 2,933,390 and 3,635,721, condensation products of aromaticorganic acid and formaldehyde such as those described in U.S. Pat. No.3,743,510, cadmium salts, azaindene compounds and the like. Thecombinations as described in U.S. Pat. Nos. 3,615,613, 3,615,641,3,617,295 and 3,635,721 are particularly useful.

Hydrophilic colloidal layers of the light-sensitive materials preparedby the present invention can contain water-soluble dyes as filter dyesor for various purposes including prevention of irradiation. Such dyesinclude oxonol dyes, hemioxonol dyes, styryl dyes, merocyanine dyes,cyanine dyes and azo dyes. Of these, oxonol dyes, hemioxonol dyes andmerocyanine dyes are particularly useful.

Photographic emulsion layers and other hydrophilic colloidal layers ofthe photographic light-sensitive materials of the present invention maycontain inorganic or organic hardeners. Examples of the hardeners whichcan be used include chromium salts (e.g., chromium alum, chromiumacetate, etc.), aldehydes (e.g., formaldehyde, glyoxal, glutaraldehyde,etc.), N-methylol compounds (e.g., dimethylolurea,methyloldimethylhydantoin, etc.), dioxane derivatives (e.g.,2,3-dihydroxydioxane, etc.), active vinyl compounds (e.g.,1,3,5-triacryloyl-hexahydro-s-triazine, 1,3-vinylsulfonyl-2-propanol,etc.), active halogen compounds (e.g.,2,4-dichloro-6-hydroxy-s-triazine, etc.), mucohalogenic acids (e.g.,mucochloric acid, mucophenoxychloric acid, etc.) and the like. Thesehardeners can be used alone or as a combination of two or more of them.

Photographic emulsion layers or other hydrophilic colloidal layers ofthe light-sensitive materials according to the present invention maycontain various surface active agents for a wide variety of purposes,such as for assistance of coating, prevention of static charge,improvement of sliding properties, assistance of emulsion dispersing,prevention of adhesion, improvement of photographic properties (e.g.,acceleration of development, increase in contrast and sensitivity, etc.)and the like.

Examples of surface active agents which can be used include nonionicsurface active agents, such as saponin (steroid type), alkylene oxidederivatives (e.g., polyethylene glycol, polyethyleneglycol/polypropylene glycol condensates, polyethylene glycol alkylethers or polyethylene glycol alkylaryl ethers, polyethylene glycolesters, polyethylene glycol sorbitan esters, polyalkylene glycolalkylamines or amides, polyethylene oxide adducts of silicone, etc.),glycidol derivatives (e.g., alkenylsuccinic polyglycerides, alkylphenolpolyglycerides, etc.), fatty acid esters of polyhydric alcohols, alkylesters of sugars, etc.; anionic surface active agents containing acidicgroups, e.g., a carboxyl group, a sulfo group, a phospho group, asulfuric ester group, a phosphoric ester group, etc., such asalkylcarboxylates, alkylsulfonates, alkylbenzenesulfonates,alkylnaphthalenesulfonates, alkylsulfates, alkylphosphates,N-acyl-N-alkyltaurines, sulfosuccinates, sulfoalkylpolyoxyethylene alkylphenyl ethers, polyoxyethylene alkylphosphates, etc.; amphoteric surfaceactive agents, such as amino acids, aminoalkylsulfonic acids, aminoalkylsulfates or phosphates, alkylbetaines, amine oxides, etc.; and cationicsurface active agents, such as alkylamine salts, aliphatic or aromaticquaternary ammonium salts, heterocyclic quaternary ammonium salts, e.g.,pyridinium imidazolium, etc., aliphatic or heterocyclic phosphonium orsulfonium salts, and the like.

Photographic emulsion layers of the photographic light-sensitivematerials according to the present invention may contain, for example,polyalkylene oxides or derivatives thereof (e.g., ethers, esters,amines, etc.), thioether compounds, thiomorpholines, quaternary ammoniumsalt compounds, urethane derivatives, urea derivatives, imidazolederivatives, 3-pyrazolidones and the like for the purpose of increasingsensitivity or contrast or accelerating development. Specific examplesof such compounds are disclosed in, for example, U.S. Pat. Nos.2,400,532, 2,423,549, 2,716,062, 3,617,280, 3,772,021 and 3,808,003 andBritish Pat. No. 1,488,991, etc.

Binders or protective colloids which can be used in emulsion layers orintermediate layers of the photographic light-sensitive materials of thepresent invention include gelatin to advantage, but other hydrophiliccolloids can also be employed.

For example, usable hydrophilic colloids include proteins, such asgelatin derivatives, graft polymers of gelatin and other high polymers,albumin, casein, etc.; cellulose derivatives, such as hydroxyethylcellulose, carboxymethyl cellulose, cellulose sulfates, etc.; sugarderivatives such as sodium alginate, starch derivatives, etc.; and awide variety of synthetic hydrophilic high molecular weight polymers,such as polyvinyl alcohol, partially acetylated polyvinyl alcohol,poly-N-vinylpyrrolidone, polyacrylic acid, polymethacrylic acid,polyacrylamide, polyvinylimidazole, polyvinylpyrazole, etc., andcopolymers containing comonomers which constitute the above-describedpolymers.

Photographic emulsion layers of the photographic light-sensitivematerials according to the present invention can contain color formingcouplers, i.e., compounds capable of forming color by oxidative couplingwith aromatic primary amine developers (e.g., phenylenediaminederivatives, aminophenol derivatives, etc.) in color developmentprocessing. For example, such color forming couplers include magentacouplers, such as 5-pyrazolone couplers, pyrazolobenzimidazole couplers,cyanoacetylcumarone couplers, open chain acylacetonitrile couplers,etc.; yellow couplers, such as acylacetamide couplers (e.g.,benzoylacetanilides, pivaloylacetanilides, etc.), etc.; and cyancouplers, such as naphthol couplers, phenol couplers, etc. It ispreferable that these couplers have hydrophobic groups called ballastgroups in their molecule and are thereby rendered nondiffusible. Thecouplers may be either 4-equivalent or 2-equivalent with respect tosilver ions. Moreover, they may be colored couplers having a colorcorrecting effect or couplers capable of releasing developmentrestrainers with the progress of development (DIR couplers).

In addition to the DIR couplers, colorless DIR coupling compounds whichyield colorless products upon coupling and release developmentrestrainers may also be used.

The light-sensitive materials prepared in accordance with the presentinvention may contain hydroquinone derivatives, aminophenol derivatives,gallic acid derivatives, ascorbic acid derivatives, etc., as color fogpreventing agents.

Hydrophilic colloidal layers of the light-sensitive materials preparedin accordance with the present invention may contain ultravioletabsorbents. Examples of ultraviolet absorbents which can be usedinclude, for example, benzotriazole compounds substituted with arylgroups (as described in U.S. Pat. No. 3,533,794); 4-thiazolidonecompounds (as described in U.S. Pat. Nos. 3,314,794 and 3,352,681);benzophenone compounds (as described in Unexamined Published JapanesePatent Application No. 2784/71); cinnamic acid esters (as described inU.S. Pat. Nos. 3,705,805 and 3,707,375); butadiene compounds (asdescribed in U.S. Pat. No. 4,045,229); benzoxidole compounds (asdescribed in U.S. Pat. No. 3,700,455) and the compounds as described inU.S. Pat. No. 3,499,762 and Unexamined Published Japanese PatentApplication No. 48535/79. Ultraviolet absorbing couplers (e.g.,α-naphthol type cyan forming couplers) or ultraviolet absorbing polymersmay also be used. These ultraviolet absorbents may be mordanted in aspecific layers.

In carrying out the present invention, the following known fadingpreventing agents can be used in combination. Further, color imagestabilizing agents can be used individually or as a combination of twoor more thereof. Examples of known fading preventing agents includehydroquinone derivatives, gallic acid derivatives, p-alkoxyphenols,p-oxyphenol derivatives, bisphenols, etc.

Silver halide photographic emulsions according to the present inventioncan further contain other various additives, such as whitenessincreasing agents, desensitizing agents, plasticizers, lubricants,matting agents, oils, mordants and the like.

Specific examples of these additives are given in Research DisclosureNo. 176, pp. 22-31 (RD-17643), (December, 1978), etc.

Photographic emulsions prepared by the present invention can be used invarious color and black-and-white silver halide light-sensitivematerials, such as color positive materials, color papers, colornegative materials, color reversal materials (the emulsion to be usedmay or may not contain couplers), photographic light-sensitive materialsfor a photomechanical process (e.g., lith films), light-sensitivematerials for CRT (Cathode Ray Tube) display, light-sensitive materialsfor X-ray recording (particularly, screen type films and non-screen typefilms), printout materials and heat developable light-sensitivematerials. The emulsions according to the present invention can also beemployed in a colloid transfer process, a silver salt diffusion transferprocess, a dye transfer process, a silver dye bleaching process, etc.

Exposure for obtaining a photographic image can be carried out in aconventional manner. For example, any of various known light sources(including infrared rays), such as natural light (sunlight), a tungstenlamp, a fluorescent lamp, a mercury lamp, a xenon arc lamp, a carbon arclamp, a xenon flash lamp, a cathode ray tube flying spot, alight-emitting diode, laser beams (e.g., a gas laser, YAG laser, dyelaser, semiconductor laser, etc.) and the like can be used. The exposuremay also be effected using light emitted from fluorescent substancesexcited by electron beams, X-rays, γ-rays, α-rays, etc. Suitableexposure times which can be used include not only exposure timescommonly used in cameras ranging from about 1/1,000 to about 1 sec, butalso exposure times shorter than 1/1,000 sec, e.g., about 1/10⁴ to about1/10⁶ sec as with xenon flash lamps or cathode ray tubes. Exposure timeslonger than 1 sec can also be used. The spectral composition of thelight employed for exposure can be controlled using color filters, ifdesired.

Photographic processing of the light-sensitive materials according tothe present invention can be carried out by known methods with knownprocessing solutions as described in, for example, Research Disclosure,No. 176, pp. 28-30 (RD-17643). Any photographic processing, whether forthe formation of silver images (black-and-white photographic processing)or for the formation of dye images (color photographic processing), canbe employed according to the end use of the light-sensitive material.Processing temperatures are generally selected from the range of from18° C. to 50° C., but temperatures lower than 18° C. or higher than 50°C. may also be used.

In some cases, other known developing methods, such as heat development,can be employed.

BEST MODE FOR CARRYING OUT THE INVENTION

The present invention will now be illustrated in greater detail withreference to the typical examples.

EXAMPLE 1

To an aqueous 2.8% gelatin solution (1 liter) containing 0.1 mol ofsodium chloride and 2.3 mmol of 3,6-dithia-1,8-octanediol, which waskept at 60° C. with stirring, were added 750 ml of 1.8M silver nitratesolution and a mixed solution of an aqueous 2.0M sodium chloridesolution and 0.46M potassium bromide over a period of 50 min by thedouble jet method while controlling the pAg level. 2 Minutes after theaddition of the silver nitrate solution and the aqueous sodium chloridesolution was started, addition of 100 ml of 2.0 mM solution of5-[2-(3-ethylnaphtho[2,1-d]oxazoline-2-ylidene)vinylidene]-3-heptyl-1-phenyl-2-thiohydantoin(D-1) was simultaneously started. Then, 120 ml of aqueous 3% hydrogenperoxide solution was added and the resulting solution was stirred at70° C. for 20 min. The resulting emulsion was washed with water anddesalted, followed by sulfur sensitization with sodium thiosulfate. Theso-obtained silver chloride emulsion grains were rectangular crystalshaving a mean diameter of 1.0 μm and a (100) face. (Emulsion A).

Then, a similar silver chloride emulsion was obtained for comparativepurposes in a manner similar to the above process except that theaqueous hydrogen peroxide was not employed. The obtained emulsion wassubjected to sulfur sensitization similar to the above. (Emulsion B).

To each of the thus-obtained Emulsions A and B, the following agentswere sequentially added and the resulting emulsion was coated on acellulose acetate film and dried to obtain Samples 51 and 52:

Stabilizer: 4-Hydroxy-6-methyl-1,3,3a,7-tetraazaindene

Hardener: Sodium 2,4-dichloro-6-hydroxy-s-triazine

Coating Aid: Sodium dodecylbenzenesulfonate

The so-obtained samples were each exposed to light through an opticalwedge through a separation filter (Eastman Kodak Wratten Filter 36B forblue light; Fiji Film Filter BPB-55 for green light; and Fuji FilmFilter SC-60 for red light). The exposed samples were developed withEastman Kodak D-72 Developer at 20° C. for 4 min, followed by normalstopping, fixing, washing and drying procedures.

As a result, it was found that Sample 52 (Emulsion B) had greensensitivity, while Sample 51 (Emulsion A) had no green sensitivity,showing that the dye had been completely decomposed and removed.

Both Emulsions A and B had approximately the same sensitivity to bluelight, and decrease in sensitivity due to the oxidative decomposition bythe deactivating agent of the present invention was not seen.

Then, a red sensitizing dye,(5,5'-dichloro-9-ethyl-3,3'-di(sulfopropyl)thiacarbocyanine.sodium salt(D-19)), was added to each of Emulsions A and B. To the resultingmixtures were added the above-described stabilizer, hardener and coatingaid and the obtained emulsions were coated on cellulose acetate films toobtain Samples 53 and 54. These samples were exposed to light through anoptical wedge through a separation filter, followed by developmentprocessing in a similar manner to the above.

As a result, it was found that Sample 53 (Emulsion A) had sufficientsensitivity to red light, while Sample 54 (Emulsion B) had reducedsensitivity, because the dye employed in the grain formation was stillpresent therein, thus preventing the adsorption of the red sensitizingdye.

As described above, the present invention has made it possible to removethe dye employed in the grain formation by using the deactivating agentof the present invention without causing deterioration of photographicproperties. As a result, it has become possible to freely prepare, asrequired, a silver halide emulsion which has sensitivity to wavelengthsdifferent from those of the dye employed in the grain formation.

EXAMPLE 2

To 1 liter of aqueous 2% gelatin solution containing 2.1 mmol ofpotassium bromide which was kept at 60° C. with stirring were added 16.7ml of 1.18M silver nitrate solution and 11.7 ml of a mixed solution of1.26M potassium bromide and 1.28M sodium chloride by the double jetmethod at a constant rate over 20 sec. The stirring was continued forfurther 3 min 40 sec, during which period 63 mmol of ammonium nitrateand 0.15 mol of ammonia were added. Then, 1 liter of 1.18M silvernitrate solution and a mixed solution of potassium bromide and sodiumchloride having the same concentration as above were added by the doublejet method over 50 min, while keeping the electric potential of thereaction mixture at -30 mV (silver-saturated calomel electrode). Oneminute after the recommencement of the addition of the silver nitratesolution and the mixed solution of potassium bromide and sodiumchloride, simultaneous addition of 400 ml of a methanol solution of 1 mMsodium3-[5-chloro-2-{2-[5-chloro-3-(3-sulfonatopropyl)benzoxazoline-2-ylidenemethyl]-1-butenyl}-3-benzoxazolio]-propanesulfonate(D-14) was started at a constant rate over 48 min. Then, 200 ml aqueous3% hydrogen peroxide was added and the resulting mixture was stirred for20 min. After washing and desalting, the resulting emulsion wassubjected to gold-sulfur sensitization using sodium thiosulfate,chloroauric acid and potassium thiocyanate. The so-obtained emulsion hada mean grain diameter of 0.82 μm and was a highly monodispersed emulsioncomprising grains of a (111) face only. (Emulsion C).

Emulsion D was obtained in a manner similar to Emulsion C, except that180 mmol of potassium persulfate was used instead of hydrogen peroxide.

Next, Comparative Emulsion E was prepared in a manner similar toEmulsion C except that neither the dye nor hydrogen peroxide wasemployed.

The thus-obtained emulsions had a broad grain size distribution and werecomprised of a mixture of various crystal forms such as a cube, anoctahedron and a tetradecahedron.

Next, Emulsions D and E were subjected to gold-sulfur sensitizationusing soidum thiosulfate, chloroauric acid and potassium thiocyanate ina manner similar to that for Emulsion C to ensure that the threeemulsions had the same degree of sensitivity.

To the so-obtained emulsions, the following agents were sequentiallyadded and the resulting emulsions were each coated on cellulose acetatefilms and dried to obtain Samples 61, 62 and 63:

Yellow Coupler:α-Pivaloyl-α-(2,4-dioxo-5,5'-dimethyloxazolidine-3-yl)-2-chloro-5-[α-2,4-di-t-amylphenoxy-butanamido]acetanilide

Stabilizer: 4-Hydroxy-6-methyl-1,3,3a,7-tetraazaindene

Hardener: Sodium 2,4-dichloro-6-hydroxy-s-triazine

Coating Aid: Sodium Dodecylbenzenesulfonate

The samples were exposed to light through an optical wedge via aseparation filter as used in Example 1, followed by developmentprocessing as shown below. The results are shown in Table 1. Therelative sensitivity represents the relative value of the reciprocal ofthe exposure amount required for providing a density of +0.5 fog, withthe value obtained by Sample 61 with respect to blue light taken as 100.

                  TABLE 1                                                         ______________________________________                                                          Relative        Relative                                                      Sensitivity     Sensitivity                                                   to              to                                          Sample No. Fog    Blue Light  γ                                                                           Green Light                                 ______________________________________                                        Sample 61  0.06   100         2.3 0                                           (Emulsion C)                                                                  Sample 62  0.06   100         2.3 0                                           (Emulsion D)                                                                  Sample 63  0.28   100         1.5 0                                           (Emulsion E)                                                                  ______________________________________                                    

As is apparent from Table 1, Emulsions C and D of the present inventionhad no green sensitivity, and had harder contrast and low fog in theblue sensitive area as compared with Emulsion E.

The harder contrast is presumably accounted for by the fact that thegrain size distribution has become narrower by using the dye in theformation of the grains. The lower fog is presumably explained by thefact that because of the uniform octahedron crystals, fog generation wasreduced. In addition to this, the dye was deactivated by thedeactivating agent and became incapable of preventing the subsequentlyadded additives from exerting their effects. As a result, the emulsionshad sufficient sensitivity in spite of the low fog.

    ______________________________________                                        Processing     Time       Temperature                                         ______________________________________                                        Color Development                                                                            2 min 30 sec                                                                             33° C.                                       Bleach-Fix     1 min 30 sec                                                                             "                                                   Washing        2 min      "                                                   Drying                                                                        ______________________________________                                    

    ______________________________________                                        Composition of the Color Developer                                            ______________________________________                                        Benzyl Alcohol           15     ml                                            Sodium Sulfite           5      g                                             Potassium Bromide        0.5    g                                             Hydroxylamine Sulfate    2.0    g                                             Sodium Carbonate         30.0   g                                             Sodium Nitrilotriacetate 2.0    g                                             4-Amino-3-methyl-N--(β-methane-                                                                   5.0    g                                             sulfonamido)ethylaniline                                                      Water to make            1,000  ml                                                                   pH 10.1                                                ______________________________________                                    

    ______________________________________                                        Composition of the Bleach-Fix Bath                                            ______________________________________                                        Ammonium Thiosulfate   105    g                                               Sodium Sulfite         2      g                                               Sodium-Iron EDTA       40     g                                               Sodium Carbonate (H.sub.2 O)                                                                         5      g                                               Water to make          1,000  ml                                                                   pH 7                                                     ______________________________________                                    

EXAMPLE 3

Potassium4-[5-chloro-2-{2-[1-(2-hydroxyethyl)-3-(2-pyridyl)-2-thiohydantoin-5-ylidene]vinylidene}-benzoxazoline-3-yl]butanesulfonate(D-5) (Emulsion F) or

3-carboxymethyl-5-[2-(3-ethylthiazolidine-2-ylidene)vinylidene]rhodanine(D-7) (Emulsion G) or

potassium2-[5-(3-ethylbenzothiazoline-2-ylidene)rhodanine-3-yl]ethanesulfonate(D-3) (Emulsion H) was employed instead of the cyanine dye used inExample 2.

After grains were formed using these dyes, an aqueous hydrogen peroxidesolution was added to oxidize and deactivate these dyes, followed bywashing, desalting and gold-sulfur sensitization.

Emulsion F was comprised of grains having (110) and (100) faces;

Emulsion G was comprised of grains also having (110) and (100) faces;and

Emulsion H was comprised of grains having only a (111) face.

The dye used for grain formation in each of the above emulsions had beenremoved by the deactivating agent of the present invention, and as aresult, the emulsions can be spectrally sensitized with respect to lighthaving wavelengths different from the dyes used, according to thedesired end use.

EXAMPLE 4

To 600 ml of 3.3% gelatin solution containing 1.2 mmol of potassiumiodide, 7.6 mmol of potassium bromide and 4.7 mmol3,6-dithia-1,8-octanediol which was kept at 53° C. with stirring wereadded 900 ml of 1.56M silver nitrate solution and a mixed solution of1.81M potassium bromide and 0.023M potassium iodide by the double jetmethod over 40 min, while controlling the pAg level. Two minutes afterthe addition of the silver nitrate solution was started, 500 ml of 1 mMsolution of3-ethyl-2-[2-(1-ethyl-2-phenylindole-3-yl)vinyl]-6-nitrobenzothiazoliumbromide (D-24) as a desensitizing dye was simultaneously added at aconstant rate over 38 min. Then, 50 ml of 3% hydrogen peroxide solutionand 300 mg of potassium tungstate were added and the resulting mixturewas stirred at 50° C. for 20 min. After washing and desalting, theresulting emulsion was subjected to gold-sulfur sensitization withsodium thiosulfate, potassium chloroauric acid and potassiumthiocyanate. The so-obtained silver iodobromide emulsion was highlymonodispersed and comprised of tetradecahedron grains having a meandiameter of 0.58 μm. (Emulsion I).

Another silver iodobromide emulsion was prepared for comparativepurposes in a manner similar to the above, except that neither hydrogenperoxide nor potassium tungstate was added. (Emulsion J).

Still another silver iodobromide emulsion was prepared for comparativepurposes in a manner similar to Emulsion I, except that the addition of3-ethyl-2-[2-(1-ethyl-2-phenylindole-3-yl)vinyl]-6-nitrobenzothiazoliumbromide, hydrogen peroxide and potassium tungstate was omitted. Thisemulsion was comprised of tetradecahedron grains having a mean diameterof 0.60 μm, but the grains were more rounded as compared with the grainsof Emulsions I and J and the emulsion was less monodispersed than theother two. (Emulsion K).

To each of Emulsions I, J and K were added the following agents and theresulting emulsion was coated on a cellulose acetate film and dried toobtain Samples 81, 82 and 83:

Sensitizing Dye: Sodium3-[5-chloro-2-{2-[5-phenyl-3-(3-sulfonatopropyl)benzoxazoline-2-ylidenemethyl]-1-butenyl}-3-benzoxazolio]propanesulfonate(D-15)

Magenta Coupler:1-(2,4,6-Trichlorophenyl)-3-[3-(2,4-di-t-amylphenoxyacetamido)benzamido]-5-pyrazolone

Antifoggant: 1-Phenyl-5-mercaptotetrazole

Stabilizer: 4-Hydroxy-6-methyl-1,3,3a,7-tetraazaindene

Hardener: 1,3-Bisvinylsulfonylhydroxypropane

Coating Aid: Sodium p-dodecylbenzenesulfonate, and sodiump-nonylphenoxypoly(ethyleneoxy)propanesulfonate

Next, the so-obtained samples were exposed to light through a yellowfilter, followed by color development as shown below to obtain theresults shown in Table 2.

                  TABLE 2                                                         ______________________________________                                                                Relative                                              Sample No.  Fog         Sensitivity                                                                             γ                                     ______________________________________                                        Sample 81   0.06        100       2.1                                         (Emulsion I)                                                                  Sample 82   0.05         0        --                                          (Emulsion J)                                                                  Sample 83   0.07        105       1.5                                         (Emulsion K)                                                                  ______________________________________                                    

As is apparent from Table 2, even in the case where grain formation iscarried out using a desensitizing dye, the dye can be completelydeactivated by an oxidizing agent of the present invention, and as aresult, sufficient photographic performance can be obtained.

The development processing was performed at 38° C. in the followingmanner:

    ______________________________________                                        1. Color Development                                                                           1 min 30 sec                                                 2. Bleach        6 min 30 sec                                                 3. Washing       3 min 15 sec                                                 4. Fixing        6 min 30 sec                                                 5. Washing       3 min 15 sec                                                 6. Stabilization 3 min 15 sec                                                 ______________________________________                                    

The compositions of the processing solutions as used in the aboveprocessing are shown below:

    ______________________________________                                        Color Developer:                                                              Sodium Nitrilotriacetate 1.0    g                                             Sodium Sulfite           4.0    g                                             Sodium Carbonate         30.0   g                                             Potassium Bromide        1.4    g                                             Hydroxylamine Sulfate    2.4    g                                             4-(N--Ethyl-N--β-hydroxyethylamino)-2-                                                            4.5    g                                             methylaniline Sulfate                                                         Water to make            1      liter                                         Bleaching Solution:                                                           Ammonium Bromide         160.0  g                                             Aqueous Ammonia (28%)    25.0   cc                                            Sodium-Iron Ethylenediaminetetraacetic                                                                 130.0  g                                             Acid                                                                          Glacial Acetic Acid      14.0   cc                                            Water to make            1      liter                                         Fixer:                                                                        Sodium Tetrapolyphosphate                                                                              2.0    g                                             Sodium Sulfite           4.0    g                                             Ammonium Thiosulfate (70%)                                                                             175.0  cc                                            Sodium Bisulfite         4.6    g                                             Water to make            1      liter                                         Stabilizing Solution:                                                         Formalin                 8.0    cc                                            Water to make            1      liter                                         ______________________________________                                    

EFFECT OF INVENTION

In accordance with the present invention, silver halide photographicemulsions are prepared utilizing additives, such as dyes, sensitizers,auxiliary agents to be used upon gold sensitization, etc., and theadditives are made to undergo deactivation at the time when theirfunctions become needless and therethrough converted to those having nobad influences upon photographic characteristics of the emulsionsprepared, or to those which can be removed from the emulsions with easeby a washing treatment. Therefore, the present invention can providesilver halide photographic emulsions excellent in photographiccharacteristics using various kinds of additives effectively.

Further, a photographic light-sensitive material which can produce animage of high quality, e.g., excellent in light fastness, can beobtained using the silver halide emulsions prepared in accordance withthe present invention.

What is claimed is:
 1. A process for preparing a silver halidephotographic emulsion utilizing a dye of the kind which can be adsorbedby or react with silver halide grains within a period from the silverhalide grain forming time to just before the emulsion coating step,which further comprises using an oxidizing agent which has the abilityto act on said dye and which is selected from the group consisting ofhydrogen peroxide, adducts of hydrogen peroxide, peroxy acid salts,organic peroxides, oxidizing gases, and halogen releasing oxidizingcompounds, therethrough to lower or to extinguish its function ofabsorption or reaction at the time when the function of said dye becomessubstantially needless.
 2. A process for preparing a silver halidephotographic emulsion as in claim 1, wherein said dye is a sensitizingdye.
 3. A process for preparing a silver halide photographic emulsion asin claim 1, wherein said dye is a methine dye.
 4. A process forpreparing a silver halide photographic emulsion as in claim 1, whereinsaid dye is used in an amount of 10⁻⁸ to 10⁻² mol per mol of silverhalide.
 5. A process for preparing a silver halide photographic emulsionas in claim 1, wherein an amount of said oxidizing agent used is 1/100to 3,000 times that of the agent to be deactivated by mol.
 6. A processfor preparing a silver halide photographic emulsion as in claim 1,wherein an amount of the oxidizing agent used is 1/10 to 3,000 timesthat of said dye by mol.
 7. A process for preparing a silver halidephotographic emulsion as in claim 1, wherein the agent to be deactivatedis used within a period from at the grain forming time to at thecompletion of chemical ripening.
 8. A process for preparing a silverhalide photographic emulsion as in claim 1, wherein the agent to bedeactivated is used within a period from at the grain forming time tobefore the beginning of chemical ripening.
 9. A process for preparing asilver halide photographic emulsion as in claim 1, wherein said dye isused within a period from at the grain forming time to before thebeginning of washing step.
 10. A process for preparing a silver halidephotographic emulsion as in claim 1, wherein a reducing substance isused after using said oxidizing agent.
 11. A process for preparing asilver halide photographic emulsion as in claim 1, wherein saidoxidizing agent is used in the presence of a catalyst.